I think deception was always part of humanity. Without it, we would be killed off by the rest of the group, or even killed by the very creature we bothered not to deceive. (Put simply, lying is a tactic that keeps us alive, so I think I have no choice but to get used to it)

Your youth shows. When I was young, people lied, but not as a matter of course, and not everybody did it.
Blame the rise of atheism, as the prime cause, along with left-wing ideology and its attendant epidemic of insecurity.

I can categorically state that lying is extremely counterproductive, in the long term, although few realize it, and will find themselves unable to do anything else.
The day I decided to abandon dishonesty was the day my entire existence changed.
Highly, highly recommended.

Are you sure that so few people lied in your day? Human nature seems to be the one thing that hasn't changed drastically. I can't really tell what thinggs were like in the past, because you were there, and not me, but I don't think that lying could have sprung up so easily by the actions of certain people. Politicians and leaders have always lied. However, I do understand why you would dislike the left side of the current establishment. I'm fine with being socially liberal as long as one doesn't forego equality for revenge. (i.e. the radical feminists who have gone so far in their attempt to gain legal equality that they want to emasculate all men, or particular people of color who are so bitter over their prior treatment that they take to hating whites). I'm curious as to how atheism brought the lying epidemic, because usually, atheists focus on what they see and know. Like, how they dwell more on scientific discovery than the potential existence of a higher being. I don't exactly know much of this, because I'm not an atheist.

Reverence for God formed a baseline for any and all human behavior. The commandments informed every Christian. Thou shalt not bear false witness, so most people didn't, and only a few did when they figured God wasn't looking.
Take God out of the formula, and there remains no reason to not do anything you feel like doing.
Lying for perceived advantage is an obvious course.

Except it doesn't work. It does deep damage, usually unnoticed by the liar. The overall result is a life that diverges from Reality, and so it doesn't work.
Banish lying, and you get back on course, in line, and oriented with the flow of Reality. Your life works.

I learned, today, for the hundredth-thousandth time, that a good night's sleep does more for my general well-being than any other single thing.
Overnight, I went from being a total mess, to feeling thoroughly euphoric.
The older you get, the more obvious this becomes.
The young may safely ignore this, for a while...

Puppy pregnancy syndrome is a psychosomatic illness in humans brought on by mass hysteria.

The syndrome is thought to be localized to villages in several states of India, including West Bengal, Assam, Bihar, Jharkhand, Orissa, and Chhattisgarh, and has been reported by tens of thousands of individuals.[1] It is far more prevalent in areas with little access to education.[1]

People suffering from this condition believe that shortly after being bitten by a dog, puppies are conceived within their abdomen.[1] This is said to be especially likely if the dog is sexually excited at the time of the attack.[2] Victims are said to bark like dogs, and have reported being able to see the puppies inside them when looking at water, or hear them growling in their abdomen.[1][2][3] It is believed that the victims will eventually die – especially men, who will give birth to their puppies through the penis.[2][3]

Witch doctors offer oral cures, which they claim will dissolve the puppies, allowing them to pass through the digestive system and be excreted "without the knowledge of the patient".[1][2]